What a lender asks a portfolio landlord for, and where the list comes from

At four or more mortgaged buy-to-lets, the paperwork changes shape. Instead of questions about the property you are buying, you get questions about every property you already have, plus a business plan and a cash flow forecast.

Most landlords meet this as a spreadsheet template emailed by a broker, and assume it is that lender's house style. It is not. Four of the demands are written into the regulator's own document, which means they will follow you to the next lender as well.

This sets out what the PRA expects lenders to do. It is not mortgage advice; which product or structure suits you is a question for a broker or adviser.

Where the list comes from

The Prudential Regulation Authority's supervisory statement SS13/16 treats a borrower with "four or more distinct mortgaged buy-to-let properties" as a portfolio landlord (paragraph 3.1), and says at 3.3 that "a specialist underwriting approach is appropriate".

The same paragraph then gives examples of what firms may ask for:

(a) "the borrower's experience in the buy-to-let market and their full portfolio of properties and outstanding mortgages"

(b) "the assets and liabilities of the borrower, including any tax liability referred to in paragraph 2.6"

(c) "the merits of any new lending in the context of the borrower's existing buy-to-let portfolio together with their business plan"

(d) "historical and future expected cash flows associated with all of the borrower's properties"

Two words in 3.3 are worth holding on to. The approach should be "proportionate", based on the lender's knowledge of you and your portfolio, so not every lender asks for everything. And these are "examples", not a closed list.

(a) The portfolio schedule

In practice this is one row per property, and the lender is reconciling it against credit data rather than taking your word for it: a footnote to 3.1 says firms may use their own judgement about how to verify the number of mortgaged properties, and names credit bureau data as one acceptable way.

What a row generally has to carry:

• address and ownership structure, whether personal, joint or company
• current value, and the basis for it
• lender, balance outstanding, rate, product type and end date
• current rent, and whether it is let today

"Experience in the buy-to-let market" sits in the same clause and is usually satisfied by how long you have been letting and how many, which your schedule already shows.

(b) Assets and liabilities, and the tax trap inside it

The cross-reference in 3.3(b) to paragraph 2.6 is the part that catches people. Paragraph 2.6 says:

"The PRA also expects firms to take into account any tax liability that is associated with the property. For the avoidance of doubt, this should include mortgage interest tax relief. Firms may make a simplifying assumption that all borrowers are subject to higher rate tax, but this may result in firms declining otherwise eligible borrowers."

So the regulator explicitly permits a lender to assume you are a higher-rate taxpayer when you are not, and openly acknowledges the cost: otherwise eligible people get declined.

If you are a basic-rate taxpayer with four or more mortgaged properties, that is worth raising before an application rather than after a decline, because lenders differ on whether they apply the assumption. What the restriction on deducting mortgage interest actually does to a leveraged portfolio is in our guide to Section 24 and phantom income.

One relief in the same paragraph: "Capital gains tax does not need to be included in the assessment of affordability."

Where personal income is used to support the borrowing, paragraph 2.9 says it should be counted net of income tax, National Insurance and that same tax liability, and lists the sources: employment income, "rental income (from all of the borrower's properties)", pensions, savings and investments. It also says that where the lender knows of a likely future change during the mortgage term, such as retirement, it should take that into account.

(c) The business plan

This is the item most landlords have never written, and the one where the wording is doing real work. Paragraph 3.3(c) asks for "the merits of any new lending in the context of the borrower's existing buy-to-let portfolio together with their business plan".

It is not a general statement of ambition. It is an argument for why this loan makes sense given what you already hold. The natural contents follow from that framing:

• what the portfolio is for, and over what horizon
• how this purchase changes it, and why that is an improvement rather than an addition
• concentration: how much of the portfolio sits with one lender, in one town, in one postcode, or in one property type. Paragraph 3.2 names "potential risks of property and/or geographical concentrations" as one of the reasons portfolio lending is treated as more complex, and 4.1 requires lenders to monitor concentrations. It is a live question, not a formality.
• how voids and arrears are handled when they happen

(d) Historical and future expected cash flows

The hardest of the four, because of two words.

"All." Not the subject property. Every property you own.

"Future expected." Not a record of what happened, a forecast. Known rate changes when a fixed term ends, known rent reviews, known certificate and licence renewals, and the voids you are planning for.

The historical half is the part that ought to be easy and usually is not, because it needs rent received rather than rent charged, month by month, per property, with the arrears and voids visible rather than smoothed away. A landlord who can show a clean two-year receipt history is making a much stronger case than one who can only show what the tenancy agreements say the rent should be.

What else the lender is testing

Alongside the four, the arithmetic that decides the case is the interest coverage ratio: expected monthly rent divided by monthly interest, stressed against likely future rate rises. Paragraph 2.7 says "the current industry standard is to set the minimum ICR threshold at 125%", and that the PRA does not expect its rules to reduce that.

Three details from Chapter 2 shape how your figures will be read:

• Costs are deducted before the threshold is set. Paragraph 2.5 lists what lenders should weigh: "management and letting fees, council tax, service charge, insurance, repairs, voids, utilities, gas and electrical certificates, licence fee, ground rent and any other costs associated with renting out the property irrespective of whether the borrower is an individual or a company."
• Equity does not help. Paragraph 2.2: firms "should not base their assessment of affordability on the equity in the property", nor "take account of a future increase in property prices".
• Your tenancy agreement is evidence. Paragraph 2.4 names three ways expected rental income may be verified: an independent suitably qualified valuer, automated valuation models, or "evidence of an existing rental agreement".

And paragraph 3.4 explains why two lenders can behave so differently at the same property count: each firm must have its own written policy setting out how its portfolio landlord underwriting differs from ordinary buy-to-let. The threshold is set by the regulator; the process on top of it is not.

What to have ready

Working backwards from 3.3, a portfolio landlord should be able to produce, per property and without a weekend of digging:

1. 1The schedule: address, structure, value, lender, balance, rate, product end date.
2. 2Rent received, by month, not rent charged, with arrears and voids visible.
3. 3Costs by category, matching the 2.5 list, including the certificates and licence fees most spreadsheets leave out.
4. 4The compliance position: gas, electrical and energy certificates with their dates, and any licence with its expiry. These are in the cost list and they affect a valuation as well as a council's view.
5. 5The forward view: fixed rates ending, rent reviews due, certificates and licences expiring.
6. 6The current tenancy agreements, which 2.4 makes one of only three named ways to evidence the rent.

Items 2 to 6 are what running the let produces anyway, if it is being recorded as it happens rather than reconstructed afterwards. LetCompliance keeps rent charged and received against each property, costs and receipts by category, and every certificate, licence and deposit date with its own deadline, alongside the tenancy agreements themselves.

Source: the PRA's SS13/16, Underwriting standards for buy-to-let mortgage contracts. Paragraphs 2.2, 2.4, 2.5, 2.6, 2.7, 2.9, 3.1, 3.3, 3.4 and 4.1 were read on 21 September 2026; the ones quoted here are identical in the September 2024 and January 2026 texts, and the January 2026 version takes effect on 1 January 2027.